feat: initial commit introducing NonEmptyString schema

src/non-empty-string.js

@@ -0,0 +1,18 @@
+import * as z from "zod";
+
+const NAME = "NonEmptyString";
+
+/**
+ * @returns {z.core.$ZodBranded<z.ZodString, typeof NAME, "out">}
+ */
+function t() {
+  return z.string().trim().nonempty().brand(NAME).meta({
+    description:
+      "A string that contains at least some characters after being trimmed of leading and trailing whitespace",
+    title: NAME,
+  });
+}
+
+export const NonEmptyString = t();
+/** @typedef {z.output<typeof NonEmptyString>} NonEmptyString */
+/** @typedef {z.input<typeof NonEmptyString>} NonEmptyStringInput */

src/non-empty-string.spec.js

@@ -0,0 +1,65 @@
+import { faker } from "@faker-js/faker";
+import { describe, expect, it } from "vitest";
+import { NonEmptyString } from "./non-empty-string.js";
+
+describe("NonEmptyString", () => {
+  const WHITESPACE_CHARACTERS = {
+    NEWLINE: "\n",
+    SPACE: " ",
+    TAB: "\t",
+  };
+
+  it("rejects true", () =>
+    // @ts-expect-error because only strings are valid inputs
+    expect(NonEmptyString.safeDecode(true).success).toBe(false));
+
+  it("rejects false", () =>
+    // @ts-expect-error because only strings are valid inputs
+    expect(NonEmptyString.safeDecode(false).success).toBe(false));
+
+  it("rejects integers", { repeats: 10 }, () =>
+    // @ts-expect-error because only strings are valid inputs
+    expect(NonEmptyString.safeDecode(faker.number.int()).success).toBe(false),
+  );
+
+  it("rejects bigints", { repeats: 10 }, () =>
+    // @ts-expect-error because only strings are valid inputs
+    expect(NonEmptyString.safeDecode(faker.number.bigInt()).success).toBe(
+      false,
+    ),
+  );
+
+  it("rejects floats/numbers", { repeats: 10 }, () =>
+    // @ts-expect-error because only strings are valid inputs
+    expect(NonEmptyString.safeDecode(faker.number.float()).success).toBe(false),
+  );
+
+  it("rejects arrays", () =>
+    // @ts-expect-error because only strings are valid inputs
+    expect(NonEmptyString.safeDecode([]).success).toBe(false));
+
+  it("rejects plain objects", () =>
+    // @ts-expect-error because only strings are valid inputs
+    expect(NonEmptyString.safeDecode({}).success).toBe(false));
+
+  it("rejects empty strings", () =>
+    expect(NonEmptyString.safeDecode("").success).toBe(false));
+
+  it("rejects strings containing only whitespace characters", () =>
+    expect(
+      NonEmptyString.safeDecode(
+        faker.helpers
+          .multiple(() => faker.helpers.enumValue(WHITESPACE_CHARACTERS), {
+            count: { min: 1, max: 100 },
+          })
+          .join(""),
+      ).success,
+    ).toBe(false));
+
+  it("accepts strings with at least 1 non-whitespsace character", () =>
+    expect(
+      NonEmptyString.safeDecode(
+        faker.string.alphanumeric({ length: { min: 1, max: 255 } }),
+      ).success,
+    ).toBe(true));
+});